/* * Copyright (C) 2008 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. */ package com.android.inputmethod.latin; import android.content.Context; import android.text.TextUtils; import android.util.Log; import com.android.inputmethod.keyboard.Keyboard; import com.android.inputmethod.keyboard.ProximityInfo; import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo; import java.io.File; import java.util.ArrayList; import java.util.HashMap; import java.util.HashSet; import java.util.Locale; /** * This class loads a dictionary and provides a list of suggestions for a given sequence of * characters. This includes corrections and completions. */ public class Suggest implements Dictionary.WordCallback { public static final String TAG = Suggest.class.getSimpleName(); public static final int APPROX_MAX_WORD_LENGTH = 32; public static final int CORRECTION_NONE = 0; public static final int CORRECTION_FULL = 1; public static final int CORRECTION_FULL_BIGRAM = 2; /** * Words that appear in both bigram and unigram data gets multiplier ranging from * BIGRAM_MULTIPLIER_MIN to BIGRAM_MULTIPLIER_MAX depending on the score from * bigram data. */ public static final double BIGRAM_MULTIPLIER_MIN = 1.2; public static final double BIGRAM_MULTIPLIER_MAX = 1.5; /** * Maximum possible bigram frequency. Will depend on how many bits are being used in data * structure. Maximum bigram frequency will get the BIGRAM_MULTIPLIER_MAX as the multiplier. */ public static final int MAXIMUM_BIGRAM_FREQUENCY = 127; // It seems the following values are only used for logging. public static final int DIC_USER_TYPED = 0; public static final int DIC_MAIN = 1; public static final int DIC_USER = 2; public static final int DIC_USER_HISTORY = 3; public static final int DIC_CONTACTS = 4; public static final int DIC_WHITELIST = 6; // If you add a type of dictionary, increment DIC_TYPE_LAST_ID // TODO: this value seems unused. Remove it? public static final int DIC_TYPE_LAST_ID = 6; public static final String DICT_KEY_MAIN = "main"; public static final String DICT_KEY_CONTACTS = "contacts"; // User dictionary, the system-managed one. public static final String DICT_KEY_USER = "user"; // User history dictionary for the unigram map, internal to LatinIME public static final String DICT_KEY_USER_HISTORY_UNIGRAM = "history_unigram"; // User history dictionary for the bigram map, internal to LatinIME public static final String DICT_KEY_USER_HISTORY_BIGRAM = "history_bigram"; public static final String DICT_KEY_WHITELIST ="whitelist"; private static final boolean DBG = LatinImeLogger.sDBG; private Dictionary mMainDict; private ContactsDictionary mContactsDict; private WhitelistDictionary mWhiteListDictionary; private final HashMap mUnigramDictionaries = new HashMap(); private final HashMap mBigramDictionaries = new HashMap(); private int mPrefMaxSuggestions = 18; private static final int PREF_MAX_BIGRAMS = 60; private double mAutoCorrectionThreshold; private ArrayList mSuggestions = new ArrayList(); private ArrayList mBigramSuggestions = new ArrayList(); private CharSequence mConsideredWord; // TODO: Remove these member variables by passing more context to addWord() callback method private boolean mIsFirstCharCapitalized; private boolean mIsAllUpperCase; private int mTrailingSingleQuotesCount; private static final int MINIMUM_SAFETY_NET_CHAR_LENGTH = 4; public Suggest(final Context context, final Locale locale) { initAsynchronously(context, locale); } /* package for test */ Suggest(final Context context, final File dictionary, final long startOffset, final long length, final Locale locale) { initSynchronously(context, DictionaryFactory.createDictionaryForTest(context, dictionary, startOffset, length /* useFullEditDistance */, false, locale), locale); } private void initWhitelistAndAutocorrectAndPool(final Context context, final Locale locale) { mWhiteListDictionary = new WhitelistDictionary(context, locale); addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_WHITELIST, mWhiteListDictionary); } private void initAsynchronously(final Context context, final Locale locale) { resetMainDict(context, locale); // TODO: read the whitelist and init the pool asynchronously too. // initPool should be done asynchronously now that the pool is thread-safe. initWhitelistAndAutocorrectAndPool(context, locale); } private void initSynchronously(final Context context, final Dictionary mainDict, final Locale locale) { mMainDict = mainDict; addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_MAIN, mainDict); addOrReplaceDictionary(mBigramDictionaries, DICT_KEY_MAIN, mainDict); initWhitelistAndAutocorrectAndPool(context, locale); } private static void addOrReplaceDictionary(HashMap dictionaries, String key, Dictionary dict) { final Dictionary oldDict = (dict == null) ? dictionaries.remove(key) : dictionaries.put(key, dict); if (oldDict != null && dict != oldDict) { oldDict.close(); } } public void resetMainDict(final Context context, final Locale locale) { mMainDict = null; new Thread("InitializeBinaryDictionary") { @Override public void run() { final Dictionary newMainDict = DictionaryFactory.createDictionaryFromManager( context, locale); mMainDict = newMainDict; addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_MAIN, newMainDict); addOrReplaceDictionary(mBigramDictionaries, DICT_KEY_MAIN, newMainDict); } }.start(); } // The main dictionary could have been loaded asynchronously. Don't cache the return value // of this method. public boolean hasMainDictionary() { return mMainDict != null; } public ContactsDictionary getContactsDictionary() { return mContactsDict; } public HashMap getUnigramDictionaries() { return mUnigramDictionaries; } public static int getApproxMaxWordLength() { return APPROX_MAX_WORD_LENGTH; } /** * Sets an optional user dictionary resource to be loaded. The user dictionary is consulted * before the main dictionary, if set. This refers to the system-managed user dictionary. */ public void setUserDictionary(Dictionary userDictionary) { addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_USER, userDictionary); } /** * Sets an optional contacts dictionary resource to be loaded. It is also possible to remove * the contacts dictionary by passing null to this method. In this case no contacts dictionary * won't be used. */ public void setContactsDictionary(ContactsDictionary contactsDictionary) { mContactsDict = contactsDictionary; addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_CONTACTS, contactsDictionary); addOrReplaceDictionary(mBigramDictionaries, DICT_KEY_CONTACTS, contactsDictionary); } public void setUserHistoryDictionary(Dictionary userHistoryDictionary) { addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_USER_HISTORY_UNIGRAM, userHistoryDictionary); addOrReplaceDictionary(mBigramDictionaries, DICT_KEY_USER_HISTORY_BIGRAM, userHistoryDictionary); } public void setAutoCorrectionThreshold(double threshold) { mAutoCorrectionThreshold = threshold; } private static CharSequence capitalizeWord(final boolean all, final boolean first, final CharSequence word) { if (TextUtils.isEmpty(word) || !(all || first)) return word; final int wordLength = word.length(); final StringBuilder sb = new StringBuilder(getApproxMaxWordLength()); // TODO: Must pay attention to locale when changing case. if (all) { sb.append(word.toString().toUpperCase()); } else if (first) { sb.append(Character.toUpperCase(word.charAt(0))); if (wordLength > 1) { sb.append(word.subSequence(1, wordLength)); } } return sb; } protected void addBigramToSuggestions(SuggestedWordInfo bigram) { mSuggestions.add(bigram); } private static final WordComposer sEmptyWordComposer = new WordComposer(); public SuggestedWords getBigramPredictions(CharSequence prevWordForBigram) { LatinImeLogger.onStartSuggestion(prevWordForBigram); mIsFirstCharCapitalized = false; mIsAllUpperCase = false; mTrailingSingleQuotesCount = 0; mSuggestions = new ArrayList(mPrefMaxSuggestions); // Treating USER_TYPED as UNIGRAM suggestion for logging now. LatinImeLogger.onAddSuggestedWord("", Suggest.DIC_USER_TYPED, Dictionary.UNIGRAM); mConsideredWord = ""; mBigramSuggestions = new ArrayList(PREF_MAX_BIGRAMS); CharSequence lowerPrevWord = prevWordForBigram.toString().toLowerCase(); if (mMainDict != null && mMainDict.isValidWord(lowerPrevWord)) { prevWordForBigram = lowerPrevWord; } for (final Dictionary dictionary : mBigramDictionaries.values()) { dictionary.getBigrams(sEmptyWordComposer, prevWordForBigram, this); } // Nothing entered: return all bigrams for the previous word int insertCount = Math.min(mBigramSuggestions.size(), mPrefMaxSuggestions); for (int i = 0; i < insertCount; ++i) { addBigramToSuggestions(mBigramSuggestions.get(i)); } SuggestedWordInfo.removeDups(mSuggestions); return new SuggestedWords(mSuggestions, // TODO: Just assuming the suggestions that came from the bigram prediction are // valid now. Need to assign a correct value for typedWordValid. true /* typedWordValid */, false /* hasAutoCorrectionCandidate */, false /* allowsToBeAutoCorrected */, false /* isPunctuationSuggestions */, false /* isObsoleteSuggestions */); } // TODO: cleanup dictionaries looking up and suggestions building with SuggestedWords.Builder public SuggestedWords getSuggestedWords( final WordComposer wordComposer, CharSequence prevWordForBigram, final ProximityInfo proximityInfo, final int correctionMode) { LatinImeLogger.onStartSuggestion(prevWordForBigram); mIsFirstCharCapitalized = wordComposer.isFirstCharCapitalized(); mIsAllUpperCase = wordComposer.isAllUpperCase(); mTrailingSingleQuotesCount = wordComposer.trailingSingleQuotesCount(); mSuggestions = new ArrayList(mPrefMaxSuggestions); final String typedWord = wordComposer.getTypedWord(); final String consideredWord = mTrailingSingleQuotesCount > 0 ? typedWord.substring(0, typedWord.length() - mTrailingSingleQuotesCount) : typedWord; // Treating USER_TYPED as UNIGRAM suggestion for logging now. LatinImeLogger.onAddSuggestedWord(typedWord, Suggest.DIC_USER_TYPED, Dictionary.UNIGRAM); mConsideredWord = consideredWord; if (wordComposer.size() <= 1 && (correctionMode == CORRECTION_FULL_BIGRAM)) { // At first character typed, search only the bigrams mBigramSuggestions = new ArrayList(PREF_MAX_BIGRAMS); if (!TextUtils.isEmpty(prevWordForBigram)) { CharSequence lowerPrevWord = prevWordForBigram.toString().toLowerCase(); if (mMainDict != null && mMainDict.isValidWord(lowerPrevWord)) { prevWordForBigram = lowerPrevWord; } for (final Dictionary dictionary : mBigramDictionaries.values()) { dictionary.getBigrams(wordComposer, prevWordForBigram, this); } if (TextUtils.isEmpty(consideredWord)) { // Nothing entered: return all bigrams for the previous word int insertCount = Math.min(mBigramSuggestions.size(), mPrefMaxSuggestions); for (int i = 0; i < insertCount; ++i) { addBigramToSuggestions(mBigramSuggestions.get(i)); } } else { // Word entered: return only bigrams that match the first char of the typed word final char currentChar = consideredWord.charAt(0); // TODO: Must pay attention to locale when changing case. // TODO: Use codepoint instead of char final char currentCharUpper = Character.toUpperCase(currentChar); int count = 0; final int bigramSuggestionSize = mBigramSuggestions.size(); for (int i = 0; i < bigramSuggestionSize; i++) { final SuggestedWordInfo bigramSuggestion = mBigramSuggestions.get(i); final char bigramSuggestionFirstChar = (char)bigramSuggestion.codePointAt(0); if (bigramSuggestionFirstChar == currentChar || bigramSuggestionFirstChar == currentCharUpper) { addBigramToSuggestions(bigramSuggestion); if (++count > mPrefMaxSuggestions) break; } } } } } else if (wordComposer.size() > 1) { final WordComposer wordComposerForLookup; if (mTrailingSingleQuotesCount > 0) { wordComposerForLookup = new WordComposer(wordComposer); for (int i = mTrailingSingleQuotesCount - 1; i >= 0; --i) { wordComposerForLookup.deleteLast(); } } else { wordComposerForLookup = wordComposer; } // At second character typed, search the unigrams (scores being affected by bigrams) for (final String key : mUnigramDictionaries.keySet()) { // Skip UserUnigramDictionary and WhitelistDictionary to lookup if (key.equals(DICT_KEY_USER_HISTORY_UNIGRAM) || key.equals(DICT_KEY_WHITELIST)) continue; final Dictionary dictionary = mUnigramDictionaries.get(key); dictionary.getWords(wordComposerForLookup, this, proximityInfo); } } final CharSequence whitelistedWord = capitalizeWord(mIsAllUpperCase, mIsFirstCharCapitalized, mWhiteListDictionary.getWhitelistedWord(consideredWord)); final boolean hasAutoCorrection; if (CORRECTION_FULL == correctionMode || CORRECTION_FULL_BIGRAM == correctionMode) { final CharSequence autoCorrection = AutoCorrection.computeAutoCorrectionWord(mUnigramDictionaries, wordComposer, mSuggestions, consideredWord, mAutoCorrectionThreshold, whitelistedWord); hasAutoCorrection = (null != autoCorrection); } else { hasAutoCorrection = false; } if (whitelistedWord != null) { if (mTrailingSingleQuotesCount > 0) { final StringBuilder sb = new StringBuilder(whitelistedWord); for (int i = mTrailingSingleQuotesCount - 1; i >= 0; --i) { sb.appendCodePoint(Keyboard.CODE_SINGLE_QUOTE); } mSuggestions.add(0, new SuggestedWordInfo( sb.toString(), SuggestedWordInfo.MAX_SCORE)); } else { mSuggestions.add(0, new SuggestedWordInfo( whitelistedWord, SuggestedWordInfo.MAX_SCORE)); } } mSuggestions.add(0, new SuggestedWordInfo(typedWord, SuggestedWordInfo.MAX_SCORE)); SuggestedWordInfo.removeDups(mSuggestions); final ArrayList suggestionsList; if (DBG) { suggestionsList = getSuggestionsInfoListWithDebugInfo(typedWord, mSuggestions); } else { suggestionsList = mSuggestions; } // TODO: Change this scheme - a boolean is not enough. A whitelisted word may be "valid" // but still autocorrected from - in the case the whitelist only capitalizes the word. // The whitelist should be case-insensitive, so it's not possible to be consistent with // a boolean flag. Right now this is handled with a slight hack in // WhitelistDictionary#shouldForciblyAutoCorrectFrom. final boolean allowsToBeAutoCorrected = AutoCorrection.allowsToBeAutoCorrected( getUnigramDictionaries(), consideredWord, wordComposer.isFirstCharCapitalized()); boolean autoCorrectionAvailable = hasAutoCorrection; if (correctionMode == CORRECTION_FULL || correctionMode == CORRECTION_FULL_BIGRAM) { autoCorrectionAvailable |= !allowsToBeAutoCorrected; } // Don't auto-correct words with multiple capital letter autoCorrectionAvailable &= !wordComposer.isMostlyCaps(); if (allowsToBeAutoCorrected && suggestionsList.size() > 1 && mAutoCorrectionThreshold > 0 && Suggest.shouldBlockAutoCorrectionBySafetyNet(typedWord, suggestionsList.get(1).mWord)) { autoCorrectionAvailable = false; } return new SuggestedWords(suggestionsList, !allowsToBeAutoCorrected /* typedWordValid */, autoCorrectionAvailable /* hasAutoCorrectionCandidate */, allowsToBeAutoCorrected /* allowsToBeAutoCorrected */, false /* isPunctuationSuggestions */, false /* isObsoleteSuggestions */); } private static ArrayList getSuggestionsInfoListWithDebugInfo( final String typedWord, final ArrayList suggestions) { final SuggestedWordInfo typedWordInfo = suggestions.get(0); typedWordInfo.setDebugString("+"); double normalizedScore = BinaryDictionary.calcNormalizedScore( typedWord, typedWordInfo.toString(), typedWordInfo.mScore); final int suggestionsSize = suggestions.size(); final ArrayList suggestionsList = new ArrayList(suggestionsSize); suggestionsList.add(typedWordInfo); // Note: i here is the index in mScores[], but the index in mSuggestions is one more // than i because we added the typed word to mSuggestions without touching mScores. for (int i = 0; i < suggestionsSize - 1; ++i) { final SuggestedWordInfo cur = suggestions.get(i + 1); final String scoreInfoString; if (normalizedScore > 0) { scoreInfoString = String.format("%d (%4.2f)", cur.mScore, normalizedScore); normalizedScore = 0.0; } else { scoreInfoString = Integer.toString(cur.mScore); } cur.setDebugString(scoreInfoString); suggestionsList.add(cur); } return suggestionsList; } // TODO: Use codepoint instead of char @Override public boolean addWord(final char[] word, final int offset, final int length, int score, final int dicTypeId, final int dataType) { int dataTypeForLog = dataType; final ArrayList suggestions; final int prefMaxSuggestions; if (dataType == Dictionary.BIGRAM) { suggestions = mBigramSuggestions; prefMaxSuggestions = PREF_MAX_BIGRAMS; } else { suggestions = mSuggestions; prefMaxSuggestions = mPrefMaxSuggestions; } int pos = 0; // Check if it's the same word, only caps are different if (StringUtils.equalsIgnoreCase(mConsideredWord, word, offset, length)) { // TODO: remove this surrounding if clause and move this logic to // getSuggestedWordBuilder. if (suggestions.size() > 0) { final SuggestedWordInfo currentHighestWord = suggestions.get(0); // If the current highest word is also equal to typed word, we need to compare // frequency to determine the insertion position. This does not ensure strictly // correct ordering, but ensures the top score is on top which is enough for // removing duplicates correctly. if (StringUtils.equalsIgnoreCase(currentHighestWord.mWord, word, offset, length) && score <= currentHighestWord.mScore) { pos = 1; } } } else { if (dataType == Dictionary.UNIGRAM) { // Check if the word was already added before (by bigram data) int bigramSuggestion = searchBigramSuggestion(word,offset,length); if(bigramSuggestion >= 0) { dataTypeForLog = Dictionary.BIGRAM; // turn freq from bigram into multiplier specified above double multiplier = (((double) mBigramSuggestions.get(bigramSuggestion).mScore) / MAXIMUM_BIGRAM_FREQUENCY) * (BIGRAM_MULTIPLIER_MAX - BIGRAM_MULTIPLIER_MIN) + BIGRAM_MULTIPLIER_MIN; /* Log.d(TAG,"bigram num: " + bigramSuggestion + " wordB: " + mBigramSuggestions.get(bigramSuggestion).toString() + " currentScore: " + score + " bigramScore: " + mBigramScores[bigramSuggestion] + " multiplier: " + multiplier); */ score = (int)Math.round((score * multiplier)); } } // Check the last one's score and bail if (suggestions.size() >= prefMaxSuggestions && suggestions.get(prefMaxSuggestions - 1).mScore >= score) return true; while (pos < suggestions.size()) { final int curScore = suggestions.get(pos).mScore; if (curScore < score || (curScore == score && length < suggestions.get(pos).codePointCount())) { break; } pos++; } } if (pos >= prefMaxSuggestions) { return true; } final StringBuilder sb = new StringBuilder(getApproxMaxWordLength()); // TODO: Must pay attention to locale when changing case. if (mIsAllUpperCase) { sb.append(new String(word, offset, length).toUpperCase()); } else if (mIsFirstCharCapitalized) { sb.append(Character.toUpperCase(word[offset])); if (length > 1) { sb.append(word, offset + 1, length - 1); } } else { sb.append(word, offset, length); } for (int i = mTrailingSingleQuotesCount - 1; i >= 0; --i) { sb.appendCodePoint(Keyboard.CODE_SINGLE_QUOTE); } suggestions.add(pos, new SuggestedWordInfo(sb, score)); if (suggestions.size() > prefMaxSuggestions) { suggestions.remove(prefMaxSuggestions); } else { LatinImeLogger.onAddSuggestedWord(sb.toString(), dicTypeId, dataTypeForLog); } return true; } // TODO: Use codepoint instead of char private int searchBigramSuggestion(final char[] word, final int offset, final int length) { // TODO This is almost O(n^2). Might need fix. // search whether the word appeared in bigram data int bigramSuggestSize = mBigramSuggestions.size(); for (int i = 0; i < bigramSuggestSize; i++) { if (mBigramSuggestions.get(i).codePointCount() == length) { boolean chk = true; for (int j = 0; j < length; j++) { if (mBigramSuggestions.get(i).codePointAt(j) != word[offset+j]) { chk = false; break; } } if (chk) return i; } } return -1; } public void close() { final HashSet dictionaries = new HashSet(); dictionaries.addAll(mUnigramDictionaries.values()); dictionaries.addAll(mBigramDictionaries.values()); for (final Dictionary dictionary : dictionaries) { dictionary.close(); } mMainDict = null; } // TODO: Resolve the inconsistencies between the native auto correction algorithms and // this safety net public static boolean shouldBlockAutoCorrectionBySafetyNet(final String typedWord, final CharSequence suggestion) { // Safety net for auto correction. // Actually if we hit this safety net, it's a bug. // If user selected aggressive auto correction mode, there is no need to use the safety // net. // If the length of typed word is less than MINIMUM_SAFETY_NET_CHAR_LENGTH, // we should not use net because relatively edit distance can be big. final int typedWordLength = typedWord.length(); if (typedWordLength < Suggest.MINIMUM_SAFETY_NET_CHAR_LENGTH) { return false; } final int maxEditDistanceOfNativeDictionary = (typedWordLength < 5 ? 2 : typedWordLength / 2) + 1; final int distance = BinaryDictionary.editDistance(typedWord, suggestion.toString()); if (DBG) { Log.d(TAG, "Autocorrected edit distance = " + distance + ", " + maxEditDistanceOfNativeDictionary); } if (distance > maxEditDistanceOfNativeDictionary) { if (DBG) { Log.e(TAG, "Safety net: before = " + typedWord + ", after = " + suggestion); Log.e(TAG, "(Error) The edit distance of this correction exceeds limit. " + "Turning off auto-correction."); } return true; } else { return false; } } }